Today road traffic noise is the dominant source in urban areas.
Imagine that more than 65 % of the European population have an A-weighted energy equivalent sound pressure levels in front of their windows which is higher than 55 dB and still 20 % are above 65 dB.

One way to protect people is the use of noise barriers. 
The animation demonstrates the influence of the source-screen-receiver geometry on the propagation of sound. 

Keywords:
Noise barriers
Diffraction

